1. Field of the Invention
The invention relates to a backflow prevention apparatus and more particularly, to a backflow prevention apparatus having internal parts that may be removable as a unit through a lateral opening in the valve body.
2. Description of the Prior Art
Backflow prevention apparatuses are widely used to prevent undesirable flow reversal under low flow, static, back-siphonage or back pressure situations wherein clean upstream fluid sources can be contaminated by downstream fluid. Backflow prevention apparatuses typically are comprised of one or two check valves, housed within a valve housing, which undergo closure under backflow, back pressure or back siphonage conditions. The use of backflow prevention apparatus is generally required by law for cross-connected water supplies, wherein potable water could undergo contamination due to flow reversal or back pressure conditions.
Typically, in order to inspect or replace internal parts of a backflow prevention apparatus it is necessary to completely disassemble the apparatus. With current designs it may be necessary to manually remove a cover plate, thereby exposing the internal elements of the apparatus or, in the alternative, physically disconnecting the apparatus from the piping system in which it may be installed and then disassembling the apparatus. Frequently the inspection and/or repair of a backflow prevention apparatus must be done quickly and efficiently since the system to which the backflow prevention apparatus is associated must be shut down during such inspection and/or repair. Therefore, while the two designs just described may be disassembled for inspection and/or repair; however, such a process requires an inordinate amount of time.
A design for a backflow prevention apparatus is desired that would permit relatively quick and easy removal, inspection and if necessary, replacement of internal elements within the backflow prevention apparatus.
In one embodiment of the subject invention a backflow prevention apparatus is comprised of:
a) a housing having
i) a front end;
ii) a back end;
iii) a bore extending therethrough along a longitudinal axis;
iv) an opening extending laterally through the housing between the front end and the back end providing access to the bore, wherein the opening has a length along the longitudinal axis;
v) a first segment at the front end of the housing and a second segment at the back end of the housing;
vi) wherein the first segment has an inlet and an outlet; and
vii) wherein the second segment has an inlet and an outlet;
b) a first valve body having an inlet and an outlet wherein the inlet of the first valve body may be slidably sealed with the outlet of the first segment;
c) a second valve body having an inlet and an outlet, wherein the inlet of the second valve body may be slidably sealed with the outlet of the first valve body and wherein the outlet of the second valve body may be slidably sealed with the inlet of the second segment;
d) wherein the first valve body and the second valve body are slidably positioned relative to one another within the opening such that;
1) in an elongated position, the combined length along the longitudinal axis between the first valve body inlet and the second valve body outlet is greater than the longitudinal length of the opening, thereby securing the valve bodies within the opening and
2) in a collapsed position, the combined longitudinal length is less than the longitudinal length of the opening, thereby making the valve bodies removable from within the opening.
In a second embodiment of the subject invention a backflow prevention apparatus is comprised of:
a) a housing having
i) a front end;
ii) a back end;
iii) a bore extending therethrough along a longitudinal axis;
iv) an opening extending laterally through the housing between the front end and the back end providing access to the bore, wherein the opening has a length along the longitudinal axis;
v) a first segment at the front end of the housing and a second segment at the back end of the housing;
vi) wherein the first segment has an inlet and an outlet; and
vii) wherein the second segment has an inlet and an outlet;
b) a first valve body having an inlet and an outlet wherein the inlet of the first valve body may be slidably sealed with the outlet of the first segment;
c) an intermediate valve body having an inlet and an outlet wherein the inlet of the intermediate body may be slidably sealed with outlet of the first valve body;
d) a second valve body having an inlet and an outlet and a length therebetween, wherein the inlet of the second valve body may be slidably sealed with the outlet of the intermediate body and wherein the outlet of the second valve body may be slidably sealed with the inlet of the second segment; and
e) wherein the first valve body, the intermediate valve body and the second valve body are slidably positioned relative to one another within the opening such that
1) in an elongated position, the combined length along the longitudinal axis between the first valve body inlet and the second valve body outlet is greater than the longitudinal length of the opening, thereby securing the first valve body, the intermediate valve body and the second valve body with a water-tight seal within the opening and
2) in a collapsed position, the combined length along the longitudinal axis between the first valve body inlet and the second valve body outlet is less than the longitudinal length of the opening, thereby making the first valve body, the intermediate valve body and the second valve body removable from within the opening.
The subject invention is also directed to a method for assembling a backflow prevention apparatus, wherein the apparatus has
a) a housing having
i) a front end;
ii) a back end;
iii) a bore extending therethrough along a longitudinal axis;
iv) an opening extending laterally through the housing between the front end and the back end providing access to the bore, wherein the opening has a length along the longitudinal axis;
v) a first segment at the front end of the housing and a second segment at the back end of the opening;
vi) wherein the first segment has an inlet and an outlet; and
vii) wherein the second segment has an inlet and an outlet;
b) a first valve body having an inlet and an outlet wherein the inlet of the first valve body may be slidably sealed with the outlet of the first segment;
c) a second valve body having an inlet and an outlet wherein the inlet of the second valve body may be slidably sealed with the outlet of the first valve body and wherein the outlet of the second valve body may be slidably sealed with the inlet of the second segment, wherein the method comprises the steps of:
A) sliding the first valve body and the second valve body together until their combined length is less than the length of the opening thereby defining a collapsed unit;
B) positioning the collapsed unit within the housing through the opening of the housing; and
C) elongating the collapsed unit until the inlet of the first valve body engages and is slidingly sealed with the outlet side of the first segment and until the outlet of the second valve body engages and is slidingly sealed with the inlet of the second segment, thereby defining an elongated unit having a sealed bore extending through the first segment, the first valve body, the second valve body and the second segment.
The subject invention additionally is directed to a method for assembling a backflow prevention apparatus, wherein the apparatus has
a) a housing having
i) a front end;
ii) a back end;
iii) a bore extending therethrough along a longitudinal axis;
iv) an opening extending laterally through the housing between the front end and the back end providing access to the bore, wherein the opening has a length along the longitudinal axis;
v) a first segment at the front end of the housing and a second segment at the back end of the opening;
vi) wherein the first segment has an inlet and an outlet; and
vii) wherein the second segment has an inlet and an outlet;
b) a first valve body having an inlet and an outlet wherein the inlet of the first valve body is slidably sealed with the outlet of the first segment;
c) an intermediate valve body having an inlet and an outlet wherein the inlet of the intermediate body is slidably sealed with the outlet of the first valve body; and
d) a second valve body having an inlet and an outlet wherein the inlet of the second valve body is slidably sealed with the outlet of the intermediate body and wherein the outlet of the second valve body is slidably sealed with the inlet of the second segment; wherein the method comprises the steps of:
A) sliding the first valve body, the intermediate valve body and the second valve body together until their combined length is less than the length of the opening thereby defining a collapsed unit;
B) positioning the collapsed unit within the housing through the opening of the housing; and
C) elongating the collapsed unit until the inlet of the first valve body engages and is slidingly sealed with the outlet side of the first segment and until the outlet of the second valve body engages and is slidingly sealed with the inlet of the second segment, thereby defining an elongated unit having a sealed bore extending through the first segment, the first valve body, the intermediate valve body, the second valve body and the second segment.